Bump sphinxcontrib-serializinghtml from 1.1.5 to 2.0.0 (#321)

Bumps [sphinxcontrib-serializinghtml](https://github.com/sphinx-doc/sphinxcontrib-serializinghtml) from 1.1.5 to 2.0.0.
- [Release notes](https://github.com/sphinx-doc/sphinxcontrib-serializinghtml/releases)
- [Changelog](https://github.com/sphinx-doc/sphinxcontrib-serializinghtml/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinxcontrib-serializinghtml@1.1.5...2.0.0)

---
updated-dependencies:
- dependency-name: sphinxcontrib-serializinghtml
  dependency-type: indirect
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>